I made the stretcher panels from pieces of 3/4" oak plywood.
I could have left the plywood end grain visible, but in a moment
of vanity I decided to add some cherry edge trim.

Using the dry-fit legs and jaws as a template, I cut the stretcher
panels to their final size and then cut the tenons on each side.
I laid out the leg mortises, drilled out the waste using a Forstner
bit and cleaned it up with a chisel and router plane.